#include<stdio.h>
#include<math.h>
int main()
{
    int x;
    printf("please input x=");
    scanf("%d",&x);
    if(x<60)
        printf("The level is:E\n");
    else if(60<=x<=69)
        printf("The level is:D\n");
    else if(70<=x<=79)
        printf("The level is:C\n");
    else if(80<=x<=89)
        printf("The level is:B\n");
    else if(90<=x<=100)
        printf("The level is:A\n");
    return 0;
}
